Kronos Bio, Inc. announced the presentation of new data from its ongoing Phase 1/2 study, KB-0742-1001, a first-in-human, open-label dose escalation and cohort expansion study of KB-0742 in patients with relapsed or refractory solid tumors or non-Hodgkin lymphoma, in a poster session at the 2024 American Society for Clinical Oncology (ASCO) Annual Meeting being held from May 31 ? June 4, 2024 in Chicago, Illinois and online. The poster features: Data from 103 patients with transcription factor (TF) fusion or MYC driven tumors treated with KB-0742 at 60mg (n=82) and 80 mg (n=21) three-days-on/four-days-off in escalation and expansion cohorts.

Patients enrolled in the study had received a median of three prior treatments (range: 0-9). The most frequently reported treatment-emergent adverse events (AE) were manageable mild to moderate nausea (69.9%) and vomiting (52.4%). Notably, no grade 3/4 neutropenia was observed.

Patients remained on treatment for an average of >2 cycles and a maximum of 14 completed cycles. Less than 10% of patients discontinued treatment due to adverse events. Two case studies, a platinum-resistant ovarian cancer (OC) patient, and a non-small-cell-lung cancer (NSCLC) patient with five prior lines of therapy will be presented.

These patients exhibited anti-tumor activity including stable disease responses of 71 days for the NSCLC patient and greater than 195 days for the OC patient, who continues on therapy. Pharmacokinetic modeling indicates that the 80mg four-days on three-days off dose schedule results in a greater than ten-fold increase in time above a preclinically determined efficacy threshold compared to the 60mg three-days-on four-days-off dose schedule. Based on the promising initial data presented at ASCO and the pharmacokinetic modeling the Company expects to see increased efficacy in the 80mg four-day-on, three-day-off expansion cohort which is expected to begin enrolling in the third quarter of 2024.

Preliminary efficacy data was presented at the 2023 AACR-NCI-EORTC meeting in October 2023 showing KB-0742?s on-mechanism anti-tumor activity in transcriptionally addicted tumors including a partial response at the 60mg three-days-on, four-days-off dose schedule. KB-0742 is a selective, oral inhibitor of CDK9, a key cofactor of oncogenic MYC transcription factor activity. KB-0742-1001 (NCT04718675) is a Phase 1/2 open-label dose escalation and cohort expansion study of KB-0742 as a treatment for MYC-amplified and other transcriptionally addicted relapsed or refractory solid tumors.